Regulator valve for transmission hydraulic control system



Feb. 25, 1958 c. J. LUCIA ETAL REGULATOR VALVE FOR TRANSMISSIONHYDRAULIC CONTROL SYSTEM 4 Sheets-Sheet 1 Filed March 51, 1955 0 i 1 a Ai: A Maw NW5; I, Jun

ave/mu u. A 00/4 Feb. 25, 1958 c. J. LUCIA ETAL ,8

REGULATOR VALVE FOR TRANSMISSION HYDRAULIC CONTROL SYSTEM Filed March31, 1955 4 Sheets-Sheet 2 I 3mm Feb. 25, 1958 c. J. LUCIA ETAL ,6

REGULATOR VALVE FOR TRANSMISSION HYDRAULIC CONTROL SYSTEM Filed March31, 1955 4 Sheets-Sheet s CARROLL J. Lucm .To my 2. DE L R IIN Feb. 25,1958 c, J, LUCIA ET AL 2,824,632

REGULATOR VALVE FOR TRANSMISSION HYDRAULIC CONTROL SYSTEM 4 Sheets-Sheet4 Filed March 51., 1955 CARROLL J. Lucia JbHN Z. DE Loeem United StatesPatent REGULATOR VALVE FOR TRANSMISSION HYDRAULIC CONTROL SYSTEM CarrollJ. Lucia, Birmingham, and John Z. De Lorean,

Detroit, Mich., assignors to Studebaker-Packard Corporation, Detroit,Mich, a corporation of Michigan Application March 31, 1955, Serial No.498,407

Claims. (Cl. 1923.2)

This invention relates to a control valve for a hydraulic control systemand, more particularly, it relates to a pressure regulating valve in ahydraulic control system for a vehicle transmission, which controls thepressure flow to a hydraulically operated transmission clutch.

In a control system for a vehicle transmission equipped with a torqueconverter and a converter lockup clutch, for example, the applicants newvalve operates to admit a predetermined maximum pressure to theconverter. The valve is also operatively responsive to changes topressure in the control system in order to effect a reduced pressureflow to the converter while the lock-up clutch is engaged. It will beappreciated that a minimum pressure flow to the converter is requiredwhen the latter is inactivated, in order to lubricate and cool theworking parts and also to maintain the converter for readiness foroperation at all times.

The applicants have devised a simplified and inexpensively manufacturedvalve for the above purpose which is described below in conjunction witha transmission control system similar to that disclosed in the Mc-Farland, Lucia and De Lorean patent application No. 498,404, dated March31, 1955.

For a further understanding of the invention, reference may be had tothe accompanying drawings in which:

Figures 1 and 2 disclose a schematic view of a hydraulic control systemfor operating the various brakes and clutches of a vehicle transmission;

Figure 3 is an enlarged view in section of the governor regulator valveshown in Figure 2;

Figure 4 is an enlarged sectional view of the throttle valve shown inFigure 2;

Figure 5 is an enlarged sectional view of the throttle limit valve shownin Figure 2;

Figure 6 is an enlarged sectional view of the direct shift throttlevalve shown in Figure 2;

Figure 7 is an enlarged sectional view of the manual selector valveshown in Figure 2;

Figure 8 is an enlarged sectional view of the reverse shuttle valveshown in Figure 2.

It is to be understood that the invention is not limited in itsapplication to the details of construction and arrangement of partsillustrated in the accompanying drawings, since the invention is capableof other embodiments and of being practiced or carried out in variousways. Also, it is to be understood that the terminology employed hereinis for the purpose of description and not of limitation.

With reference to Figures 2 and 2a, which diagrammatically illustratethe hydraulic control system of which the applicants new converter valveis a part, it will be seen at the front and rear pumps 130 and 220respectively are connected by a fluid pressure gallery 250. The pumpsdraw fluid from a sump and circulate it through the hydraulicallyoperated transmission controls,

as well as the lubrication system of the transmission unit.

The front pump is drivingly connected with the engine drive shaft in thecustomary manner and is thus adapted to supply fluid under pressure togallery 250 whenever the vehicle engine is running. The rear pump 220 isdriven by the output shaft of the engine in the conven tional manner,and thus operates only when the output shaft is driven. Check valves 254and 256 are disposed at opposite ends of the gallery adjacent the pumpoutlet conduits 13% and 220a connecting with the front and which isreciprocally mounted within a housing 262.

The valve 260 has four lands 260a, 260b, 2600, 260d; the first three allbeing equal diameter but smaller than the diameter of land 260d. Thevalve 260 is urged to the left by a spring 266 retained between theright hand end of the valve and the adjacent housing wall. The action ofspring 266 is supplemented by a torque responsive throttle limit valvepressure admitted to the right hand end of housing 262 through conduit268, and which exerts a force against the right side of valve laud 260d.Gallery fiuid pressure is delivered through conduit 270 to the left handend of the housing and urges the valve 260 to the right against theaction of the spring 266 and the throttle limit pressure. In addition,the movement of valve 260 to the right is assisted by the modulatingvalve fluid pressure delivered to the housing through conduit 272, whichexerts a force against the left side of land 260d. Restricted orifices268a and 272a are connected in series with conduits 268 and 272,respectively, to minimize the effect of surging of the fluid pressuretherein on the valve operation.

When the front pump is operating and the gallery pressure exceeds apredetermined limit, the valve 260 is moved a suflicient distance to theright so that land 2601) uncovers conduit 274 connecting with the intake275 of the front pump 130, and fluid pressure from the conduit 258 ispermitted to flow therethrough back to the front pump.

Gallery fluid pressure is also delivered to the pump regulator valve Ithrough conduit 276, and under normal operating conditions is permittedto flow between lands 26% and 2600 into conduit 278 which connects withthe converter valve 1. In the event the rear pump 220 builds upexcessive gallery pressures, valve 260 is moved to its extremeright-hand position, and as a result, land 2600 uncovers vent line 280connecting with the sump 252, and the gallery pressure from conduit 276is vented therethrough.

From the above description it will be appreciated that the pumpregulator valve I controls the pressure of, the gallery fluid, and alsodetermines which of the two pumps, independently or in combination, areto be operatively connected to the controlsystem. In addition, if thereis a large demand of fluid pressure while the rear pump 220 isoperating, the regulator valve will op eratively connect the front pumpwith the system, Also, it will be seen that the applicants regulator.valve and gallery arrangement insures that sufiicient pressure is firstdelivered to the gallery to operate the transmisa Patented Feb. 25, 1958 sion clutches and brakes, before pressure is admitted to theconverter valve J.

The converter valve I serves the dual function of maintaining thedesired high fluid pressure in the converter A when the lock-up clutch Bis inoperative and the converter is rendered operative, and a fixedpercentage lower fluid pressure in the converter when the converterlock-up clutch B is engaged. The converter valve includes a valve 290with two lands 290a and 2901) of equal diameter, and an elongated valvestem 292 which extends into a separately enclosed fluid pressure chamber294 housing valve 296. A spring 298 interposed between a spring stopmember 300 and the right hand end of valve 296, tends to hold the leftside of valve 296 in contact with the right hand end of valve 290. Whenthe direct shift valve K is opened the pressure of the fluid in chamber294 moves the valve 296 to the right, against the action of spring. 298.Also, the fluid pressure from conduit 302 exerts a force against the endof the valve stem 292, thereby tending to move valve 290 to the left,but with less force than when the spring 298 forces the valve 296against stem 292 of valve 290. When the direct shift valve K is closedand no fluid pressure is delivered through conduit 302, valve 296 bearsagainst valve stem 292, and spring 298 moves both valves 296 and 290 tothe left.

As valve 290 is moved to the left, land 290a uncovers conduit 278connecting with the pump regulator valve 1, and fluid pressure isadmitted between lands 290a and 290b, through conduit 304 to theconverter A, and thence through a restricted orifice 310 in theconverter outlet conduit 312 connecting with a cooler 314, which in turnconnects with the sump. The fluid pressure contained in line 304 is alsoconducted to the left hand end of the valve 290 through connectingconduit 306, which tends to move the valve 290 to the right against theaction of spring 298, thereby etfecting a reduction in the fluidpressure delivered to the converter as land 290a meters the flow throughconduit 278.

When gallery pressure is delivered to chamber 294 through conduit 302,the force exerted thereby against the right end of valve stem 292, whichis of smaller diameter than valve 296, permits valve 290 to move to theright so that land 2901: meters a reduced pressure through conduit 278to the converter A. By this arrangement a fixed percentage of lowerfluid pressure is admitted to the converter for lubrication and coolingpurposes when the latter is inoperative and the converter lock-up clutchis engaged. Therefore, it will be seen that in the ap- 1 plicantscontrol system arrangement, the operative converter lock-up clutchpressure and the converter pressure are self compensating in the eventof pressure leakage in the lock-up clutch, when the latter is engaged.If the pressure delivered to the converter exceeds a predeterminedlimit, valve 290 is moved a suflicient distance to the right so thatland 290a covers conduit 2'78 and land 290 uncovers vent line 308, withthe result that the pressure in conduit 304 is vented to the sump.Thereafter, spring 298 and the gallery fiuid pressure if any, returnsvalve 290 to its normal metering position.

It will be appreciated that the desired percentage differential in fluidpressure delivered to the converter when the latter is activated orrendered inoperative, may be obtained by varying the differentials inthe diameters of the valve stem 292 and valve 296. In addition, themaximum fluid pressure delivered to the converter through the conduit304 may be controlled by varying the tension of spring 298.

A speed responsive fluid pressure as determined by the speed of theoutput shaft 139 delivered by the governor valve H is utilized inconjunction with the torque responsive fluid pressure as determined bythe position of the accelerator pedal delivered by the throttle valve Lto operate the various controls in the hydraulic systern, which in turnoperate the transmission brakes and clutches, in a manner subsequentlyto be described.

With specific reference to Figure 3, it will be seen that the governorvalve H includes a lightweight high speed valve 320 and a heavierweighted low speed valve 322 which are reciprocably mounted in valvechambers 324 and 326, respectively. The valve chambers 324 and 326 arefixedly mounted on output shaft 139, and the centrifugal force generatedby their rotation tends to move the vaives 320 and 322 away from and atright angles to the axis of the shaft. The centrifugal force acting uponthe high speed valve 320 is supplemented by a spring 328 retained Withinthe housing 324 between the underside of the valve and a spring stopmember 330 which bears against the output shaft.

Fluid pressure from the outlet conduit 22011 of the rear pump 220 isdelivered to the high speed valve chamber 324 through conduit 332. Thespring 328 normally positions the valve 320 so that land 320a uncoversconduit 332, and thus the rear pump pressure is permitted to flow out ofthe valve chamber through conduit 334 to the low speed governor valvechamber 326. Pressure from conduit 334 is also delivered to the upperend of the high speed valve chamber 324 through connecting conduit 336,and tends to move valve 320 inwardly against the action of the spring328 and the centrifugal force, if any. As a result, the flow of fluidpressure from conduit 332 is metered by the relative movement of valveland 320a in respect thereto. If the pressure in conduit 334 exceeds apredetermined maximum limit for any driving speed, valve 320 is movedinwardly a sufficient distance by the fluid pressure at its outer end sothat land 320a covers conduit 332 and land 32% uncovers vent port 338,whereupon, fluid pressure from line 334 flows through vent port 338communicating with the sump.

It will be appreciated that the fluid pressure in conduit 334 at leastmust be equal to the force exerted by spring 328 before the high speedvalve 320 commences to regulate the governor output pressure. It willalso be appreciated that the relatively light weight high speed governorvalve is adapted to provide a more sensitive pressure regulation at highvehicle speeds than would be possible using only a heavier weighted lowspeed valve, next to be described.

The low speed valve 322 has three lands; lands 322a and 32215, which aredisposed near its outer end and center portion, respectively, being ofequal but smaller diameter than land 3220 disposed adjacent the outputshaft 139. When the output shaft 139 is rotated, valve 322 is movedoutwardly by centrifugal force and land 32% uncovers conduit 334whereupon fluid pressure is permitted to flow between lands 32211 and3220 to the governor outlet conduit 340. At the same time, the fluidpressure in chamber 326 tends to move valve 322 inwardly, due to thelarger diameter of land 322a, and as a result, land 3221: meters thepressure flow from conduit 334. It will be appreciated that the lowspeed valve 322 is adapted to provide a relatively steep increase ingovernor output pressure, due to its heavier weight and the differentialarea of lands 32211 and 3220.

If the pressure in conduit 340 exceeds a predetermined limit, valve 322is moved inwardly a sufficient distance so that land 32% covers conduit334. Land 3221) also uncovers a port 342 communicating with the outletconduit 340 through connecting conduit 344. Thus, fluid pressure ispermitted to flow through port 342 to a vent port 346 until the pressurein conduit 340 is sufficiently reduced and valve 322 is returned to itsnormal metering position.

With specific reference to Figure 4, it will be seen that the throttlevalve L includes a cylindrical housing 360 with pressure outlet ports362 and 364 near its opposite ends, and with a centrally disposedpressure inlet port 366 connected with gallery 250 by conduit 368. Asleeve shaped piston 370 having lands 370a and 370b of equal diameterformed near its center and right hand end, respectively, is reciprocablymounted within the housing 360. The piston 370 has a radial vent port372 near its left hand end, and a radial pressure port 374 near itscenter. A throttle idle spring 376 disposed about the left end of piston370, is loosely retained between the left side of land 370a and theadjacent housing end wall 378. It will be noted that spring 376 acts tomove the piston 37th to the right, only when the piston is movedsufliciently to the left that spring 376 bears against the housing wall378. The piston 370 is urged to the left by spring 380 disposed at itsopposite end. The spring 380 is retained between the right hand housingend wall 382 and a cylindrically shaped spring retainer 384, which fitsabout the right end of piston 370 and abuts land 370b.

A valve 390 having lands 390a, 390b, and 390C, is slidably mountedwithin the piston 370, in axial alignment therewith. A plunger 392 ismounted for reciprocal movement through an opening 394 in the housingend wall 382 and extends through the cylindrical spring retainer 384.The left end of the plunger 392 is received within the piston 370 and isconnected to the right end of valve 390 by a ball and socket coupling396. The opposite end of the plunger 392 is connected by suitablelinkage 397 to an engine accelerator pedal 398, as showndiagrammatically in Figure 2a. Thus, the position of the plunger 392 andvalve 390 relative to the piston 370, is dependent upon the enginethrottle setting. The leftward movement of the piston 370 and valve 390towards the full closed throttle position is limited by an adjustablestop member 399.

When the plunger 392 and valve 390 are moved toward the full closedthrottle position, spring 380 moves piston 370 sufliciently to the leftso that the throttle idle spring 376 bears against the housing wall 378.As a result, piston 370 is positioned so that the right hand land 3701)closes the outlet port 364 and, the left hand land 390a of valve 390partially opens the piston vent port 372, and land 39Gb opens port 374.Under these conditions, the gallery pressure from conduit 368 ispermitted to flow into a passageway 400 formed between piston 370 andvalve 390. A portion of the fluid pressure in passageway 400 flowsthrough vent port 372 to the sump, and the remainder flows through port402 in the piston, and thence to the housing outlet port 362. Thepressure delivered to the outlet port 362 exerts a force against theleft side of land 370a urging the piston to the right, and port 374 isthereby partially closed by valve land 39%.

When the valve 390 is moved, a relatively small distance toward the openthrottle position, spring 376 no longer bears against the housing wall378, and thus the fluid pressure at the outlet port 362 alone acts tomove the piston 370 to the right against the action of spring 380. As aresult, a reduced pressure flow is metered through port 374. It will beappreciated that throttle valve outlet pressure remains approximately indirect proportion to the speed increasing position of the acceleratorpedal, and is therefore substantially proportional to the torque outputof the engine. In this connection, it will be seen that throttle idlespring 376 is utilized to position the piston 370 such as to provide arapid increase in the throttle valve pressure as the engine throttle isinitially opened and a corresponding rapid increase in engine torque isdeveloped. A high throttle pressure is required under these operatingconditions to ensure the positive engagement of the transmission brakesand clutches.

When the valve and plunger are moved beyond the full throttle setting tothe kickdown position, valve land 390a closes vent port 372, and thefullgallery pressure delivered to the outlet port 362, moves the piston 370to its extreme right hand position against stop 404. As a result, land370a uncovers outlet port 364, and gallery pressure flows therethrough,into conduit 406 connecting with the lowhigh shift valve N.

. In the event the driver quickly removes his footfrorn pressure flowthrough inlet port 450.

the acceleratorpedal and the valve 390 is-moved rapidlyto the left,valve land 390a is moved momentarily beyond the-"piston, uncoveringventport'372. Thus, spring 380, unopposed by the gallery fluid pressure,rapidly returns piston 370 towards the closed throttle position.

The throttle limit valve 0 as shown in Figure 5 includes a valve 420with lands 420a and 42% disposed near its opposite ends, which ismounted for reciprocal movement withina cylindrical housing 422. Aspring 424 retained" between the left hand end of the valve 420 and theadjacent housing end wall, tends to move the valve to the right, towardsa valve stop member 426. When valve 420 bears against stop 426, an inletport 428 communicating with a throttle valve pressure conduit 430 isuncovered 'by the right hand land 420b.- The throttle valve pressure isthen permitted to flow around the valve to an outlet port 432 which isconnected with the low regulator valve R by conduit 434. Also, aspreviously described, fluid pressure is delivered to the right hand endof the pump regulator valve J, through connecting conduit 268. Inaddition, pressure from conduit 434 is delivered by branch conduit 43411to a port 436 at the right hand end of housing 422, which urges valve420 to the left against the action of'spring' 424 and land 4201) therebymeters the pressure flow through the action of spring 424 and groovedportion of valve 420 thereby meters the pressure flow through the inletport 428.

It will be appreciated that the maximum pressure which is permitted toflow through, the throttle limit valve 0 cannot exceed the force exertedby spring 424, and the maximum outlet pressure may be determined byvarying the tension of the spring. In the event of a sudden, surge ofpressure in conduit 434 and branch conduit 434a, valve 420 is moved tothe left a suflicient distance so that its left hand land 420a uncoversvent port 438 connecting with the sump, and the right hand land 42%covers inlet port 428. When the excessive fluid pressure in line; 434has been vented through port 438,

spring 424 returns valve 420 to its normal metering po-.

sition.

The direct shift throttle valve Q, as shown in Figure 6, includes acylindrical chamber or housing 440 with valve stop members 442 and 444disposed at opposite ends thereof. The housing 440 has a radiallyextending pres-.

sure inlet port 446 formed at its left hand end connecting with athrottle valve pressure conduit 448 which in turn connects with thethrottle valve outlet port 362 Another radial inlet pressure port 450 isdisposed in the side of the valve housing near its center which isconnected by branch line 448a with conduit 448. An outlet pressure port452 also formed in the side of the valve housing near its center,connects with conduit 454 communicating with the direct shift valve K.

A valve 456 having lands 456a and 456k formed in its left hand end andnear its center, respectively, is 'reciprocably mounted within thechamber 440. A spring 458 retained between the right hand end of thevalve 456 and the adjacent housing end wall, urges the valve 456 towardsthe stop member 442.

As the throttle pressure enters the valve chamber through inlet port446, the valve 456 is moved to the right against the force exerted bythe spring 458, and land 45 6b uncovers inlet port 450 and thus throttlepressure is permitted to flow between the valve lands, through theoutlet port 452 and into conduit 454. The fluid pres sure in conduit 454is delivered to the right side of land 45Gb by a branch conduit 454aconnecting with a radial port 460 near the right end of the housing. Thepressure in conduit 454 and 454a, therefore, assists spring 458 to movethe valve 456.to the left, and land 456b meters the If a surge of pressure occurs in line 454 the valve is moved momentarily to the leftagainst stop 442, and land 456b, closes the inlet port 450 and land 456auncovers vent port 462. The excess pressure in line 454 is then ventedthrough 7 the vent port'462 to" thesump until the valve is returned toits normal metering position.

From the above description, it will be apparent that the purpose of thedirect shift throttle valve Q is to deliver a pressure which is apredetermined fixed amount less than the throttle valve pressure andthis differential in pressure is determined by the tension of spring458. If for example, spring 458 has an applied force equivalent to 35pounds per square inch, the throttle valve pressure delivered throughconduit 448 must equal approximately 35 pounds per square inch beforethe valve is opened and fluid pressure is permitted to flow into conduit454. Thereafter, the pressure in conduit 454 remains approximately 35lbs. less than the throttle valve pressure as the latter is increased.

As will be seen in Figures 2 and 2a, conduit 454 from the directshiftthrottle valve Q, communicates with the right hand portion of acylindrical housing 480 of the direct shift valve K. The governorpressure conduit 340 connects with the left hand end of the housing 480,and conduits 482 and 484 communicate with the interior of its centerportion. Conduit 482 is connected with the converter lock-up clutch B,and conduit 484 connects with both the manual selector valve U and thelow-high shift valve N. I

A valve 486 is mounted for reciprocal movement within housing 480 and isnormally held in engagement with the left hand housing end wall by aspring 488 retained between the right hand end of the valve 486 and theadjacent housing end wall. The valve has five lands; lands 486a and 48Gbnear its left hand end being of equal diameter, and lands 4860, 486d,486e near its center and right hand end, respectively, being of equaldiameter and larger diameter than lands 486a and 48Gb. For the reasonsof economy and convenience of manufacturing,

the valve 486 may be formed by two or more separate valves disposed inaxial alignment.

When the engine is idling, spring 488 is assisted in moving valve 486 tothe left by the direct shift throttle pressure from conduit 454 (a fixedamount less than the throttle pressure with a minimum of 35 p; s. i.).The direct shift throttle pressure is admitted into the interior of anaxial bore 490 in the right end of the valve through a connecting radialbore 492, and reacts against the right side of valve land 486:2. Withthe valve in it's left hand position, land 486d covers conduit 484communicating with the low-high shift valve N, and conduit 482connecting with the converter lock-up clutch B is vented tothe sumpthrough vent port 494 which is uncovered by land 4866. When the governorpressure has increased sufiiciently to' move valve 486 to its right handposition within housing 430, land 48-c covers vent port 494 and land486d uncovers conduit 484. Thus, the low-high shift valve pressure fromconduit 484 is permitted to flow between lands 486c and 486a to conduit482, and thence to pressure chamber 100 in the converter lock-up clutchB. In addition, pressure from conduit 482 fiows through branch line 302to the converter valve I, which as pre viously explained meters areduced pressure flow to the converter A while the lock-up clutch B isengaged.

When the vehicle speed is decreased, and the governor pressure iscorrespondingly decreased, the throttle pressure and spring 488 move thevalve 486 to its left hand position, and the pressure in the lock-upclutch conduit 482 is vented to the sump. From the above description itwill be apparent, that the direct shift valve K serves to control theengagement of the converter lock-up. clutch B when the vehicle hasattained a predetermined driving speed.

The following paragraphs include a description of the low high shiftvalveN, the low regulator valve R, the shift regulator valve S and themodulating valve T, and a detailed explanation of their interrelatedvoperation.

, The low high shift valve N includes av cylindrical housing 500 theright hand. end of which connects. with a branch conduit 340a" of'thegovernor pressure conduit 340. The kick-down throttle valve pressureconduit 406 connects with housing 500 near its right hand end, thedirect shift valve conduit 484 and a conduit 502 communicating with thegallery 250 are both connected with the middle portion of the housing.Also, a conduit 584 is connected near its left hand end, whichcommunicates with the outlet port 362 of the throttle valve L. A bypassline 506 connects with the left hand end and center portion of thehousing interior on opposite sides of conduit in addition, the housing500 has a radial vent port 588 near its center, and vent ports 510 and5&2 disposed near its right hand end between conduits 484 and 496.

A piston 514 having an axial bore 516 in its left hand is reciprocallymounted within the left hand end of the housing 500. The piston 514 haslands 514a, 5141 and 514C at its left end, center and right end,respectively; lands 514a and 514b being of equal and slightly largerdiameter than land 5140. A spring 513 seated within the piston bore 516and retained against the left hand housing end wall 506a urges thepiston 514 to the right.

A valve 520 is reciprocably mounted in the right hand end of the housing500, and is disposed in axial alignment with piston 514. The valve 520has a land 5201: at its left hand end and a land 5201') of largerdiameter at its right hand end. Governor pressure delivered to the rightend of the housing 506 exerts a force against the right side of land520b, thereby moving valve 520 to the left, into engagement with theright end of piston 514.

As shown in Figures 2 and 2a, when the engine is idling and the manualselector valve U is placed in its neutral position, the piston 514 andvalve 520 are moved by spring 518 to the right against the right handhousing end wall 50Gb. Under these conditions, piston land 5140 uncoversthrottle pressure conduit 504 and covers the right end of the bypassconduit 506. The throttle pressure from conduit 504 upon being admittedto bore 516, assists the spring 518 in maintaining the piston in itsright hand position so that land 514i] covers the gallery pressureconduit 502, and vent ports 508, 510 and 512 are opened. As a result, nopressure can flow through conduit 484 to the direct shift valve K andthe manual selector valve U, and for reasons that will subsequently bedescribed, neither the low brake D or the high clutch E are engaged.

When the vehicle commences to move, and the governor pressure in branchconduit 340a is proportionally increased, the valve 520 and piston 514are at first slowly moved toward the left. Thus, piston land 514bpartially uncovers conduit 502, and fluid pressure is permitted to flowbetween lands 51417 and 5146 into conduit 484. It will be apparent thata metering action momentarily occurs between land 514b and conduit 502when a balance is attained between the governor pressure at the rightside, and the spring and throttle pressure on the left side, of thevalve. It will also be noted that when the low high shift valve N closesgallery conduit 502, no pressure can fiow to the converter lock-upclutch B through conduit 482 regardless of the position of the directshift valve K. A more complete description of the combined operation ofthe direct shift and the lowhigh shift valves will subsequently begiven.

As the governor pressure increases, the piston SM is moved further tothe left, and land 5140 covers the throttle pressure conduit 504, andthe fluid pressure in bore 516 is vented through by-pass line 535 tovent port 508 connecting with the sump. As a result, the piston is movedrapidly to its extreme left hand position against the left hand housingend wall 500a since spring 533, alone, opposes its movement in thisdirection. Full gallery pressure is then permitted to flow throughconduit 484, and the high range clutch E is engaged depending upon. theposition of themanual tselector. valve,.which will subsequently bedescribed in detailij In'this, connection, the governor pressure isassisted in holding the. piston 514 in its extreme left hand position,by the force of the gallery pressure reacting against the right side ofland 514k; the latter being of larger diameter than land 5146.

In the event the kick down throttle pressure is admitted to conduit 406by the throttle valve L (when the accelerator pedal is depressed beyondits full throttle position), this pressure reacts against the left sideof land 5201) of valve 520, and the latter is moved to the right, if thegovernor pressure does not then exceed a predetermined limit.Consequently, the spring 518, then being unopposed by the governorpressure, moves the piston 516 rapidly to the right. The gallerypressure conduit 502 is then covered by land 5145, and no fluid pressurecan flow through conduit 484 to the direct shift valve K. Therefore,regardless of the position of the latter, no pressure can be deliveredthrough conduit 482 to engage the converter lock-up clutch B andconsequently the converter A is activated. Also, since no pressure isdelivered through conduit 484 to the manual selector valve U (and thenceto the high range clutch and the release side of the low range brake D),the high range clutch may be inactivated and the low range brake engageddepending upon the position of the manual selector valve. A detaileddescription of the kickdown operation will be given following thedescription of the manual selector valve and its interrelated operation.

When the vehicle speed decreases, and a correspond ing lower governorpressure is delivered to the right side of the valve, the piston 514 isat first moved slowly to the right by the action of the spring 518,thereby reducing the pressure flow to conduit 484. As the governorpressure decreases further, the piston is moved sufficiently towards theright that land 514a uncovers the throttle pressure conduit. Fluidpressure is then admitted to the piston bore 516 and the piston israpidly moved thereby, to its extreme right-hand position, in engagementwith the right hand housing end wall 50Gb.

It will be apparent upon reading the subsequent paragraphs, the lagpreceding a positive, rapid movement of the piston 514, ensures that theoperative transmission brake or clutch is released before the other isengaged.

The fluid pressure admitted to conduit 484 by the lowhigh shift valve Nis conducted to the manual shift valve I]. From there it flows throughconduit 534 to the upper side of piston 535 in the low range brake D toeffect its release. A restricted orifice 536 is connected in series withconduit 534 and serves to retard the fluid pressure flow to the releaseside of'the low range brake D, for reasons subsequently to be described.The fluid pressure in conduit 534 is also conducted to the low regulatorvalve R and the shift regulator valve S, by branch conduits 538 and 540,respectively. Pressure flows from the shift regulator valve S throughconduit 542 to the piston chamber 188 in the high range clutch E,thereby effecting the engagement of the high range planetary gearsystem.

The low regulator valve R-has a cylindrical shaped housing 544 with twoclosely spaced radial ports 546 and 548 in its side. A valve 550 havinglands 550a and 55Gb near its left hand end and center portion,respectively, is reciprocably mounted within the housing. The valve 550is urged to the left by a spring 552, which is loosely disposed aboutits right hand end and retained between the right side of land 55% andthe right hand housing end wall. Throttle limit valve pressure isdelivered by conduit 434 to the left hand end of housing 544, and exertsa force against the left side of land 550a, thereby tending I to movethe valve to the right against the action of of passageway 554communicate withports 546 and 548, respectively. The tension of spring552 is such that when the. pressure delivered to the left hand end ofvalve 550 is approximately 10% of the maximum throttle limit pressure,the valve is moved to its right hand position. Under these conditions,the fluid pressure in conduit 534 may by-pass orifice 536, by flowingthrough branch conduit 538 and valve passageway 554 to port 548, andthence through conduit 556 which connects with conduit 534 at a pointbetween the low range brake D and the orifice 536.

Thus, it will be apparent that above 10% of the maximum throttle limitpressure, orifice 536 is by-passed, and the full pressure in conduit 534is utilized to effect the rapid engagement or release of the low rangebrake D. When less than 10% of the maximum throttle limit pressure isdeveloped, the low regulator valve R is closed and the pressure flowthrough conduit 534 is retarded byorifice 536, and consequently, theengagement or release of the low range brake D is momentarily delayed.It will be appreciated that under conditions of low throttle pressure,and a corresponding low engine torque, the slower release of the lowbrake will result in a smooth transition from the low to the high rangethrough the planetary gear system. At higher engine torque, however, asimilar delay in the release of the low brake, would result in thepremature failure of thehigh range clutch.

As shown in Figure 2, the shift regulator valve S includes a cylindricalhousing 558 having radially disposed pressure inlet ports 560 and 562near its center which connect with the by-pass lines 538 and branchconduit 540, respectively. The high clutch pressure conduit 542 isconnected near the left hand end of the housing 558, and a branchconduit 564 connecting therewith, delivers fluid pressure to the leftend of the housing interior. It will be noted that the pressure suppliedthrough branch conduit 540 is momentarily of lower pressure than thatdelivered throughconduit 538, because the latter by-passes therestricted orifice 536.

A piston 568 having lands 568a and 56812 near its opposite ends isreciprocably mounted within the left hand end of housing 558. The piston568 has radial ports 574 in its side which communicate with an axialbore 576 extending inwardlyfrom the left end of the piston. A valve 580with lands 580a and 58Gb near its left end and center portion,respectively, is reciprocably mounted in the right end of the housing558 in axial alignment with the piston. A spring 582 is loosely disposedabout the right end of valve 580 and is retained between the left sideof land 58012 and the adjacent housing end wall. The spring 582 urgesthe valve and piston 568 towards the left end of the housing.

When the piston is in its left hand position, pressure from the by-passconduit 538 flows freely around the valve (between lands 568a and 568b)into conduit 542. At the same time, the outlet pressure in conduit 542is delivered to the left side of piston land 568a by branch conduit 564,and the piston thereby is moved slowly towards the right first againstthe action of spring 582, and thereafter against the opposing forceexerted by the pressure admitted through conduit 54%. As the piston ismoved to the right, fluid pressure from conduit 542 fills bore 576. Theentire end surface of piston 568 is then exposed to the force of thefluid pressure, and therefore, the piston 563 is moved further to theright so that land 568a partially covers conduit 542, reducing thepressure flow in conduits 542 and 564 until a balance is substantiallyattained between the latter and the spring 532.

The fluid pressure delivered to the regulator valve 8 through conduit540 initially has no effect on the position of piston 568 because of theaction of the spring 582. When this pressure increases to a point whereit exerts a greater force against the piston and valve than spring 582,valve 580 is moved thereby to the right against the housing wall. Also,the pressure from conduit 540 reacts against the right side of piston568, moving. the latter. to

the left until a balance is reached with the increased regulator valveoutlet pressure in conduit 542 and 564; If, in the event, the pressurein conduit 542 decreases due to a leak in the high range clutch E, forexample, the piston 563 is moved to the left, thereby permitting fullgallery pressure from conduit 538, to flow between lands 568a and 56812.

From the above description it will be seen that the'shift' regulatorvalve S controls the pressure flow to the high range clutch E andassists maintaining a predetermined high pressure in conduit 542 whilethe clutchE is engaged. During a shift from the low to the high rangethrough the planetary system, for example the regulator valve S firstacts to admit an increasing gallery pressure into conduit 542 (as thepump output increases), then momentarily the pressure increase isretarded (even though the vehicle speed and gallery pressureareincreasing), and thereafter the pressure in conduit 542 is permittedto increase until it reaches the maximum gallery pressure. This delay inthe rate of pressure increase in conduit 542 allows sulficient time forthe low range brake D to be fully released before the high range clutchE is engaged.

During a downshift, pressure inconduits 540 and 534 is vented throughvent port 514 in the low high shift valve N. As the piston 568 is movedto the right the radial piston ports 574 are aligned with a vent port586, and the pressure in conduit 542 and piston bore 576 is abruptlyvented therethrough. When the pressure in conduit 542 is reduced to apoint where it produces a force approximately equal to that of spring582, the piston is moved to the left by the spring, and the remainder ofthe pressure in conduit 542 flows through conduits 538, 534, and 484 tovent port 510 in the low high shift valve N. The rapid venting action ofthe shift regulator valve S during a down-shift, ensures that the highrange clutch E is fully released before the low brake D is engaged,thereby providing a smooth transition between the planetary gear rangesand preventing the early failure of the high range clutch.

As shown in Figure 2a, the modulating valve T has a housing 610 with aninlet port 612 connected with the governor pressure conduit 340. Thehousing also has radial ports 614 and 616 in its side connecting withthe pump valve conduit 272 and a branch conduit 484a of the low-highshift valve conduit 484, respectively. The left hand end of the housingis connected withconduit 534 through a branch conduit 534a.

A valve 629 having lands 620a and 62% near its opposite ends, isreciprocably mounted within the housing 619, and is normally urgedagainst the left hand end thereof by a spring 622. The spring 622 isretained between the right end of the valve and a stop member 624 whichis fixedly mounted at the right end of the housing. When the valve ismoved to the left, land 620a opens port 612 and land 62llb closes port616. Fluid pressure is then permitted to fiow from the governor pressureconduit 340 around the valve, and into conduit 272 connecting with thepump regulator valve I. As previously explained, under these conditions,the pump regulator valve I acts to reduce the gallery pressure inaccordance with the speed of the vehicle.

When the low-high shift valve N admits fluid pressure to conduits 484,534 and 542 to activate the high range clutch E, pressure from line 534aexerts a force against the left side of the modulating valve, and thelatter is urged towards the right against the action of spring 622. Land620a then covers the inlet port 612, and land 6201; opens port 636,whereupon pressure flows from conduit 484:! to conduit 272. Aspreviously described, the pressure delivered through conduit 272 assistsin moving the pump regulator valve 260 to the right and the front pumppressure thereby is reduced. If the high range clutch E is operative andthe. pressure. in.conduit. 484a is below a with the result that thepredetermined limit the proportionately reduced pressure admitted toconduit 272 is not sufiicient to move the pump regulator valve 260 tothe right. Thus, the gallery pressure is permitted to increase, therebyensuring the high range clutch E of adequate pressure to remain fullyengaged. It will be noted that this latter condition (or relatively lowpressure in conduit 434) is mostly likely to occur when the enginetorque is high and vehicle speed is low, as for example, when startingin high range converter, and it is under these circumstances, thatmaximum gallery pressure is required to prevent the high range clutchfrom slipping.

it will be appreciated that another outstanding feature of theapplicants pump regulator valve 1 is that in combination with the closedfluid circuits connecting the various control valves and transmissionclutches and brakes with the reservoir, it acts to compensate for lossof pressure due to leakage in the high range clutch under conditions ofhigh engine torque. In this respect, it will be seen that if a leakshould occur in or near the high range clutch, the resulting loss ofpressure in lines 542, 534 and 534a will efiect the movement of themodulating valve 620 to the left due to the action of the spring 622. Asa result under conditions of high engine torque normally developed atlow engine speeds, a proportionally lower governor pressure is admittedfrom conduit 340 and conduit 272 to the regulator valve I, near the leftside of the valve land 269d. As a result, the then relatively highthrottle limit pressure delivered through conduit 268 and the force ofspring 266 tends to move the regulator valve 260 to the left, overcomingthe governor pressure, which is exerting a force in the oppositedirection. As previously explained, movement of the regulator valve tothe left causes valve land 26% to cover conduit 274 pressure in thegallery 250 is increased.

With particular reference to Figure 7, it will be seen that the manualselector valve U has a cylindrical housing 660 with radially disposedports 662, 664, 666, 668, 670, 672 and 674 along its side. Ports 662 and666 communicate with the high clutch pressure conduit 534 and a branchconduit 534a connecting therewith, respectively, and port 664communicates with a high-low shift valve pressure line 484. Ports 668and 670 connect with the low brake pressure conduit 532 and a branchconduit 532a thereof, and port 672 communicates with the gallery 250through conduit 676. Port 674 connects with conduit 678 which in turncommunicates through branch conduits 678a and 67812 with the reverseshuttle valve V and the operative side of piston 679 of the reversebrake F, respectively.

A valve 680 having lands 680a, 680b, 6800, and 680d is mounted forreciprocable movement within the housing 660, and its right hand end isconnected to a lever 682 by a pin 684, which in turn may be secured bysuitable linkage (not shown) to a conventional manual gear shift lever.By selectively positioning the gear shift lever, the driver may movevalve 680 to one of five positions, indicated generally at 686; namelydesignating the neutral or park position, indicating the normal drivingrange, D for rapid acceleration, L for low gear drive, and R forreverse.

A series of five detents 688 are formed along the left hand end of valve680 which corresponds to the five manually selectable positionsindicated above. Two spring biased ball elements 6% and 692 are mountedfor reciprocable movement at right angles to the longitudinal axis ofvalve 680, and are adapted to engage one of the five detents 683 therebyholding the valve 680 in one of its five manually selectable positions.The ball elements 690 and 692 are. housed within radially disposedcylinder chambers. 694 and 696,. respectively, which are. secured to theside of'the housing 660, near its left hand end. The elements 690 and692 are urged into engagement with the valve 'detents 688 by springs 698and 700 retained between the elements and the outer housing end walls702 and 704, respectively. Fluid pressure from the governor conduit 340is introduced through branch conduits 34% and 3400 to each of thechambers 694 and 696, respectively. Thus, when the vehicle is driven,and the governor pressure is increased accordingly, the ball elements690 and 692 are held firmly in engagement with the detents 688. Theselector valve 680 is thereby held in position and cannot beaccidentally moved while drivmg.

A radial bore 786 near the right end of the selector valve 680 isdisposed so that it is aligned with conduit 678 only when the selectorvalve is placed in the L position. The radial bore 706 connects with anaxial bore 708, which in turn communicates through suitable means (notshown) with the sump.

The reverse shutting valve V, shown in Figure 8, includes a cylindricalhousing 710 disposed in axial alignment With the longitudinal axis ofthe modulating valve housing 610, and is separated therefrom by the stopmemher 624. It will be appreciated that the two housings may be formedseparately if desired. Housing 710 has radial ports 712 and 714 formednear its opposite ends which connect with branch conduit 678a from themanual selector valve U, and conduit 716 communicating with theinoperative side of piston 679 of the reverse brake F. A branch conduit676a connects the gallery pressure conduit 67.6 with a third radial port718 formed near th middle of housing710.

, A valve 720 having lands 720a and 72Gb near its opposite ends isreciprocably mounted within the housing. The valve 720 is urged to theleft into engagement with a stop member 624 by a spring 722 retainedbetween the right end of the valve and a fixed spring retaining element726.

When the manual selector valve U is positioned in any one of its fivepositions except R reverse, the selector valve port 674 is closed and,therefore, fluid pressure cannot flow to the left side of the reverseshuttle valve 720 through conduits 678a, as a result spring 722 normallymaintains the valve 720 in its left hand positions, and gallery pressurefrom conduit 676a is perm'tted to flow between lands 720a and 72012 intoconduit 716, and thence to the upper (release) side of the reverse brakepiston 679. Thus, the reverse brake F is held positively in itsinoperative position when any of the forward driving ranges are engaged.

When pressure is admitted to the left end of housin 710 through conduit678a, valve 720 is moved to the right so that land 720a covers port 718and land 72% uncovers radial vent port 728 in the housing. Gallerypressure then flows through conduits 678 and 6781: to the under(operative) side of the reverse brake piston 679, engaging the reversebrake F. The fluid pressure on the upper side of the piston is ventedthrough line 716 and vent port 728.

The operation of the above described automatic control system is similarto that described in the copending McFarland, Lucia and De Loreanapplication Ser. No. 498,404, dated March 31, 1955.

It will be apparent that other forms of the invention may be employedwithout departing from the spirit of the invention, and it is to beunderstood that the following claims are not to be considered as limitedsolely to the details of construction and arrangement of partsillustrated and described in the specification.

What is claimed is:

1. In a hydraulic control system and a vehicle transmission comprising atorque converter, a hydraulically operated converter lock-up clutch, afluid pressure reservoir for delivering fluid pressure to the converterclutch to effect its engagement, a valve connecting with the "14reservoir and the converter to regulate thefluid pressure flow to theconverter, said valve being movable in one direction to increase thefluid pressure flow to the converter and movable in the oppositedirection to decrease the fluid pressure flow to the converter, saidvalve including means responsive to the fluid pressure delivered to theconverter to move said valve in said opposite direction, piston meansoperatively connected with said valve to movesaid valve in said onedirection, said piston means being operatively responsive to the fluidpressure delivered from the reservoir for engaging the converter lock-upclutch to effect the movement of said valve in said opposite direction.l

2. A hydraulic control system and a vehicle transmission comprising atorque converter, a hydraulically operated converter lock-up clutch, afluid pressure reservoir, a valve comprising a valve chamber havingclosed ends, an outlet port communicating with the interior of the valvechamber, a fluid passageway connecting the outlet port with theconverter, a fluid pressure return port near one end of' the valvechamber, a branch conduit connect ing the fluid passageway and thereturn port, an inlet port communicating with the interior of the valvechamber between the outlet and return ports, fluid conveying meansconnecting the inlet port with the pressure reservoir, a piston chamberdisposed near the opposite end of the valve chamber, a valve'memberreciprocably mounted within the valve chamber to meter the fluidpressure flowbetween the inlet and outlet ports; the pressure deliveredthrough said return port tending to position the valve member to reducethe pressure flow between the inlet and outlet ports, said valve memberhaving an elongated valve stem which extends through an opening in theopposite end of the valve chamber and partially into the piston chamber,a piston member of larger cross sectional area than said valve stemreciprocably mounted within said piston chamber, spring means to urgethe piston member into engagement with the valve stem, the valve memberthereby being positioned to increase the pressure flow between the inletand outlet ports of the valve chamber, a radial pressure inlet portcommunicating with the interior of the piston chamber, means to deliverfluid pressure to said pressure inlet port when the lock-up clutch isoperated to move said piston member away from said valve stem, thepressure at said return port then positioning said valve member so thata reduced fluid pressure flows to the converter.

3. A hydraulic control system and a vehicle transmission comprising atorque converter, a hydraulically operated converter lock-up clutch, afluid pressure reservoir and conduit means connecting with the controlsystem to deliver fluid pressure from the reservoir to the lock upclutch to effect its engagement, a valve comprising a housing having twochambers separated by a partition, outlet port communicating with theinterior of one chamber, a fluid passageway connected in the outlet portwith the converter, a fluid pressure return port near the end of saidone chamber opposite the partition, a branch conduit connecting thefluid passageway and return port, inlet port communicating with theinterior of said one chamber between the outlet and return ports, fluidconveying means connecting the pressure reservoir with the inlet port, avalve member reciprocably mounted with said one chamber to meter fluidpressure between said inlet and outlet ports; the pressure deliveredthrough the return port tending to move the valve member toward thepartition to reduce the pressure flow between the inlet and outletports, said valve member having an elongated valve stem reciprocablymounted through an opening in the partition and extending into thesecond chamber, a piston member of larger cross sectional area than saidvalve stem which is reciprocably mounted within said second chamber,spring means to urge the piston member toward the partition intoengagement with the valve stem, thereby moving the valve member awayfrom the partition to increase the pressure flow between the inlet andoutlet ports of said one chamber, a pressure inlet port communicatingwith the interior of the second chamber near the partition, a fluidpassageway connecting the pressure inlet port and said conduit means,whereby pressure from said conduit means to effect the engagement of theconverter clutch is also delivered to the interior of the second chamberto move the piston member away from the partition, and also to move thevalve stem and valve member towards said end of said one chamber toreduce the pressure flow between the inlet and outlet ports.

4. A hydraulic control system and a vehicle transmission comprising atorque converter, a hydraulically operated converter lock-up clutch, afluid pressure reservoir and control means to deliver fluid pressurefrom the reservoir to the lock up clutch to effect its engagement, avalve comprising a housing with closed ends having two axially alignedcylindrical chambers separated by a partition, a radially disposedoutlet port communicating with the interior of one chamber, a fluidpassageway connected in the outlet port with the converter, a radiallydisposed return port near the end of said one chamber opposite thepartition, a branch conduit connecting the fluid passageway and returnport, a radially disposed inlet port com municating with the interior ofsaid one chamber between the outlet and return ports, fluid conveyingmeans conmeeting the pressure reservoir with the inlet port, a valvemember having two lands of equal diameter reciprocably mounted withinsaid one chamber; the pressure delivered through the return port tendingto move the valve member toward the partition to reduce the pressureflow between the inlet and outlet ports, said valve member having anelongated valve stem reciprocably mounted through an opening in thepartition and extending into the second chamber, a piston member oflarger cross sectional area than said valve stem which is reciprocablymounted within said second chamber in substantially axial alignment withthe valve member, spring means retained between the piston member andthe end of the second chamber, to urge the piston member toward thepartition into engagement with the valve stem, thereby moving the valvemember away from the partition to increase the pressure flow between theinlet and outlet ports of said one chamher, a pressure inlet portcommunicating with the interior of the second chamber near thepartition, a fluid passageway connecting the pressure inlet port andsaid control means whereby pressure from said conduit means is deliveredto the interior of the second chamber to move the piston away from thepartition, and also to move the valve stem and valve member towards saidend of said one chamber to reduce the pressure flow between the inletand outlet ports.

5. Apparatus as described in claim 4 wherein said valve member has landsof equal diameter formed about its end opposite the elongated stem andnear its middle portion respectively; said valve member when .movedtoward the partition being positioned so that the end valve land coversor partially covers the inlet port and the fluid pressure deliveredthrough the inlet port flows between the valve member lands and theoutlet port.

References Cited in the file of this patent UNITED STATES PATENTS2,645,137 Roche July 14, 1953 2,655,169 Tower et al. Oct. 13, 19532,726,557 Ackerman Dec. 13, 1955

